RE: [rfc] x86, bts: improve X86_PTRACE_BTS help text
From: Metzger, Markus T
Date: Thu Oct 16 2008 - 03:13:17 EST
>From: Roland Dreier [mailto:rdreier@xxxxxxxxx]
>Sent: Donnerstag, 16. Oktober 2008 08:57
>To: Metzger, Markus T
> > config X86_DS
> > + def_bool X86_PTRACE_BTS
> > + depends on X86_DEBUGCTLMSR
>using def_bool here to get this turned on if X86_PTRACE_BTS is set
>doesn't seem scalable to more uses of X86_DS. I would have
>having X86_PTRACE_BTS select X86_DS would make more sense.
We do plan other users. Perfmon2, for example, will be using it.
I fail to see the difference between the two models.
In one case, new users would need to select X86_DS.
In the other case, new users would need to extend the def_bool clause of
The documentation recommended to use select carefuly, that's why I
picked the other one.
If people think that select is clearer, I will change it.
> > + This adds a ptrace interface to the hardware's branch
> > +
> > + Debuggers may use it to collect an execution trace of
> > + application in order to answer the question 'how did
>I get here?'.
> > + Debuggers may trace user mode as well as kernel mode.
> > +
> > + Say Y unless there is no application development on
> > + and you want to save a small amount of code size.
>This looks much better -- someone like me could read this and make an
>informed decision about the config option.
Good. I will send a patch if there is no more feedback on the select vs.
def_bool topic today.
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